What the broadcast protocol is
A Haltech Elite or Nexus ECU doesn't wait to be asked for data. It continuously sends a stream of its channels out on the CAN bus, and any device on that bus can listen in. The Haltech ECU Broadcast CAN Protocol is the specification for that stream. It lists which channels are sent, which CAN message each one lives in, and how to turn the raw bytes back into real values with the right scaling and units.
You may have seen it called the Haltech CAN Dash Protocol. That was its original name. The document was later updated and renamed to reflect what it really describes: the ECU's general data broadcast, not something that only dashes use.
What's in the stream
The broadcast carries the live engine data you'd expect to see on a gauge or in a log. Typical examples include:
- Engine speed (RPM) and throttle position
- Temperatures such as coolant and intake air
- Pressures such as manifold, oil and fuel
- Other sensor readings the ECU is measuring
Who uses it
Haltech dashes. The iC-7 and uC-10 already understand the protocol, so with a Haltech ECU and dash on the same bus you don't need to touch the document at all. Setup in NSP is covered in sourcing data for dashes in NSP.
Third-party dashes, loggers and displays. This is who the document is really for. If you're connecting a Haltech ECU to another brand's dash, a data logger or a custom display, that device has to be told how to decode each message. Some aftermarket dashes include a ready-made Haltech setting. If yours doesn't, the protocol document is what you or the dash maker will build the configuration from.
Custom projects. Anyone writing their own CAN reader, for example on a microcontroller, uses the same document to know where each value sits and how it's scaled.
Related CAN documents
The broadcast protocol only describes what the ECU sends. For the physical and general rules of Haltech's CAN network, see the Haltech CAN protocol specification. If a PD16 or CAN keypad needs to be shared between the ECU and a Haltech dash, read about multi-master CAN. Power distribution modules have their own document, the PD16 CAN protocol.
Getting the document
Need the protocol for a dash or logger integration? Ask us and we'll send over the current version, along with advice on setting up your display. If you're not sure whether your third-party dash can talk to a Haltech at all, book a free consultation and we'll check.
